Time-resolved spectra of dense plasma focus using spectrometer, streak camera, and CCD combination.

A time-resolving spectrographic instrument has been assembled with the primary components of a spectrometer, image-converting streak camera, and CCD recording camera, for the primary purpose of diagnosing highly dynamic plasmas. A collection lens defines the sampled region and couples light from the plasma into a step index, multimode fiber which leads to the spectrometer. The output spectrum is focused onto the photocathode of the streak camera, the output of which is proximity-coupled to the CCD. The spectrometer configuration is essentially Czerny-Turner, but off-the-shelf Nikon refraction lenses, rather than mirrors, are used for practicality and flexibility. Only recently assembled, the instrument requires significant refinement, but has now taken data on both bridge wire and dense plasma focus experiments.

Neuropathological diagnostic accuracy.

This study investigated variations in neuropathological diagnosis when histopathological slides are evaluated with access to all information pertinent to a case, compared with evaluation of H & E stained slides with only limited clinical information. The aim of the study is to evaluate the role of 'local' factors in reaching a definitive, neuropathological diagnosis. Each of 227 cases was reviewed by the local neuropathologist at one of three European centres with access to all clinical, radiological and histopathological data. Each case was also reviewed by a second, independent neuropathologist at another European unit, who was blinded to the local pathologist's diagnosis, and only had access to the age and sex of the patient and the location of the lesion. For the histopathological evaluation, initially he had access to H & E and GFAP stains only. Diagnoses were made using the WHO 2000 classification system and the two evaluations were classified into one of the following four categories: complete agreement; minor disagreement (not affecting treatment); minor disagreement (affecting treatment); complete disagreement. In 175 (77.1%) cases there was complete agreement between the two neuropathologists and in 18 (7.9%) cases there were non-treatment altering discrepancies in the diagnoses. Overall, there was disagreement which might potentially affect treatment in 34 (15%) of the cases. Histopathological diagnosis of the majority (85%) of brain tumours is accurate and uniform. However, histopathology is subject to a degree of interpretation. The availability of full, 'local', clinical information may be of considerable importance to the diagnostic process.

The contribution of proton magnetic resonance spectroscopy (1HMRS) to clinical brain tumour diagnosis.

Proton magnetic resonance spectroscopy (1HMRS) provides biochemical information from tissue non-invasively, and has an evolving role in brain tumour diagnosis and management. We present 100 consecutive patients with brain tumours who had single voxel 1HMRS as part of their preoperative investigations. We report the histopathological findings and the diagnostic contribution of spectroscopy in an adjunctive role. On the basis of clinical and radiological information the preoperative diagnosis was unclear or inaccurate in 26 out of 100 cases. The discrepancy was of lesion grade in 17 cases and lesion type in 9 cases. In 6 of 100 patients with brain tumours 1HMRS could have made a significant contribution to the preoperative diagnosis if used as part of the routine assessment. There is therefore a useful role for 1HMRS in the evaluation of intracranial mass lesions.

Modifying radical radiotherapy in high grade gliomas; shortening the treatment time through acceleration.

PURPOSE: To evaluate the efficacy and toxicity of accelerated radiotherapy in patients with primary high grade glioma, where acceleration is used as a means of delivering a shortened course of radical radiotherapy. PATIENTS AND METHODS: Two-hundred and eleven patients with primary high grade glioma were treated at the Royal Marsden NHS Trust between 1987 and 1997 with accelerated radiotherapy (55 Gy in 34 fractions twice daily), to planning target volume (PTV) defined as enhancing tumour and a 3 cm margin. All had histologically confirmed high grade glioma (53 anaplastic astrocytoma, 137 glioblastoma multiforme, 4 gliosarcoma, 5 gemistocytic astrocytoma, 12 high grade astrocytoma not otherwise specified). The mean Karnofsky performance status (KPS) was 90 and median age was 54 years (range 19-77). RESULTS: Of 211 patients entered, 201 were able to complete radiotherapy; 39 patients (19%) had deterioration in KPS during radiotherapy and this was transient in 11. Median survival of 211 patients was 10 months with 1 year, 2 year, and 3 year survival probabilities of 38%, 14%, and 8% respectively. Age and extent of excision were independent prognostic factors for survival. Previous comparison to matched cohort receiving 60 Gy in 30 daily fractions did not demonstrate significant survival difference. CONCLUSION: Accelerated radiotherapy is a feasible treatment approach for patients with high grade glioma. The survival and functional outcome are comparable to conventional radiotherapy and the treatment is without serious acute toxicity. While acceleration of conventional dose irradiation could be tested in randomised studies, it is unlikely this approach would result in a clinically meaningful survival benefit. Accelerated radiotherapy therefore remains one of the ways of delivering radical irradiation in patients with high grade glioma. However, it adds complexity to what is a palliative treatment regimen and the rationale and advisability should be re-examined, particularly in terms of impact on quality of life, true patient preference, and health economic considerations.

Posterior fossa meningiomas: surgical experience in 52 cases.

BACKGROUND: Early reports of the surgical management of posterior cranial fossa meningiomas (PCFM) yielded poor results with high rates of mortality and morbidity. With the advent of modern neuroimaging and microsurgical techniques the results of surgery have improved markedly, but despite these advances removal of these lesions remains a challenge. METHODS: The results of the surgical treatment of PCF meningiomas were examined with the aim to identify particular features associated with increased mortality and morbidity. RESULTS: Of 713 patients with meningioma, 52 patients were identified with PCFM. Total macroscopic excision was achieved in 44 patients (84%). Postoperative complications occurred in 28 patients (54%) with permanent sequelae in 18 (35%). There were no mortalities in the immediate postoperative period. Follow-up ranged from 14 to 174 months (mean 42), tumour has recurred in 11 patients (21%) with a long-term mortality of 11%. At their latest follow-up 41 (79%) of patients achieved Glasgow outcome scores of 4 or 5. CONCLUSIONS: Total excision of tumour should remain the goal of treatment in patients with PCFM. Despite the recent advances in preoperative planning and surgical techniques, the morbidity associated with surgery remains significant. Notwithstanding, the majority of patients achieve a good outcome with surgical treatment.

Neurenteric sinus dorsal to the thoracic spine with an associated cutaneous haemangioma: case report.

The case of an infant born with a large cutaneous haemangioma overlying the thoracic spine is presented. A small midline pit lay within the haemangioma, histological examination of which confirmed it to be a neurenteric sinus. The possible embryological origins of this rare lesion are discussed.

Endoscopic removal of a third ventricular cysticercal cyst.

We report the case of a young man who presented with acute obstructive hydrocephalus previously treated with bilateral ventriculo-peritoneal shunts. Previous magnetic resonance imaging studies were consistent with aqueduct stenosis; no intraventricular pathology was identified. Neuroendoscopy was performed in order the third ventricle and perform a third ventriculostomy. This revealed a cysticercal lesion of the third ventricle which was removed endoscopically. In addition, a third ventriculostomy was performed and both shunt systems removed. Following a course of albendazole the patient went on to make a full recovery, and currently remains shunt independent.

Haemangiopericytoma: a clinical and radiological comparison with atypical meningiomas.

A small number of haemangiopericytomas (HPCs) are compared with a group of cases labelled as atypical meningiomas (AMs) extracted from our records over a 10-year period. There was close convergence between the two groups in terms of clinical presentation. Radiologically, they were quite different. HPCs subjected to angiography demonstrated a major vascular supply from branches of the internal carotid or vertebral arteries, whereas this was not a feature of the meningioma group. Half the HPCs arose from the lateral petrosal attachment of the tentorium; all the meningiomas were parasagittal. The HPCs did not prove to be more formidable technical challenges than the meningiomas: the operative blood loss was much the same in both. The same number of recurrences and deaths occurred in the two groups at approximately the same interval during the follow-up period, making both conditions equally grave in terms of prognosis.

Multiple dural metastases from a pituitary adenoma. Case report.

Only 12 cases of pituitary tumors that metastasized within the central nervous system have been reported. A further case is presented in which the histology of the multiple dural metastases remained identical to that of the original tumor, a pituitary adenoma. The authors discuss management of these rare lesions that appear histologically benign.

Prolactinomas in men masquerading as invasive skull base tumours.

Four giant prolactin-secreting tumours invading the skull base are described. All of them occurred in men. The presenting features were sufficiently diverse to be clinically misleading. We advocate the estimation of prolactin levels before embarking on complicated skull base surgery in men where doubt remains regarding the diagnosis after clinical and radiological study.

Primary spinal malignant schwannoma.

Malignant schwannomas are uncommon primary tumours of nerve sheath origin. They are rarely found within the spine and spinal canal, and little is known about their management in this unusual location. We describe the presentation of three patients with primary spinal malignant schwannomas and discuss the surgical management.

Chondrosarcoma of the skull base: a series of eight cases.

Chondrosarcomas of the skull base are indolent, locally invasive tumors with a marked tendency to recur. Surgery is the mainstay of treatment because these tumors are generally resistant to other forms of treatment. A surgical approach with wide access to the skull base and one that is easily repeatable is required, because recurrence is common. We have used the LeFort I maxillotomy or mobilization of the zygoma at the time of craniotomy to obtain wide access to the skull base in eight cases of chondrosarcoma. Three patients have undergone subsequent procedures by us for recurrent disease. One patient died 30 days after the operation, and one has required an open repair of a cerebrospinal fluid leak. Good palliation of symptoms has been achieved in all survivors. These approaches fulfill the criteria for the surgical management of these difficult tumors by allowing excellent exposure, safe repetition if required, satisfactory palliation, and acceptable morbidity.

Gliomyosarcoma: an immunohistochemical analysis.

Tumours of mixed glial and sarcomatous elements occurring in intracranial neoplasms are well recognised and have been termed gliosarcomas. These tumours account for up to 8% of all glioblastomas. The sarcomatous elements are thought to derive from the neoplastic transformation of mesenchymal cells in or adjacent to the tumour. This transformation usually has the appearance of a fibrosarcoma or angiosarcoma. Alternative mesenchymal neoplastic differentiation may occur, however, giving rise to the appearances of chondrosarcoma and osteosarcoma. In 1969 Goldman described a case in which the sarcomatous elements of a mixed gliosarcoma appeared, on the basis of light microscopy alone, to differentiate towards skeletal muscle having the features of a rhabdomyosarcoma. He coined the term gliomyosarcoma. In 1986 Barnard et al reported a second case and demonstrated the features of rhabdomyosarcoma using the electron microscope. A further case characterised with both light microscopic and immunohistochemical techniques is reported.

Haemorrhagic cerebral metastases from malignant testicular teratoma.

Cerebral metastases from malignant testicular teratoma may show complex appearances with magnetic resonance imaging (MRI), which are consistent with changes resulting from repeated haemorrhage. Haemorrhage causes enlargement and symptomatic progression of cerebral lesions, and this can occur even when extracranial disease or other cerebral lesions remain static.

The recovery of peripheral nerves following tissue expansion.

A rat sciatic nerve model has been used to study the response of nerves to tissue expansion and their recovery at intervals up to 100 days using electrophysiology and histological methods. Tissue expansion has been shown to increase nerve length by 32% of which half remained at 100 days. Following tissue expansion the mean conduction velocity of the sciatic nerve was reduced to 30.0 +/- 1.35 m/s which represented 60.3% of control values, by 100 days the conduction velocity had almost returned to normal. Histological examination showed the cause of the reduction in function to be due to segmental demyelination without axonal degeneration, these changes returned towards normal during the recovery period but were not completely reversed by 100 days.

Recurrent dysplastic cerebellar gangliocytoma (Lhermitte-Duclos disease) presenting with subarachnoid haemorrhage.

A case of dysplastic cerebellar gangliocytoma recurring after 20 years and representing with subarachnoid haemorrhage is described. Evidence in favour of a neoplastic pathogenesis is presented.

Is peroperative smear cytology necessary for CT-guided stereotaxic biopsy?

Neuropathology is a relatively scarce resource with uneven geographical distribution, and some surgeons rely on macroscopic appearances of tissue and await later paraffin section histology for the final diagnosis. The effect of the introduction of a peroperative cytology service has been assessed in a 5-year series of CT-directed stereotaxic biopsies of intracranial mass lesions using a low cost adapted pre-CT stereotaxic frame. The technique has been mastered by 28 different surgeons with varying degrees of neurosurgical expertise and 259 procedures have been performed in 245 patients. Benign lesions were detected in 24 (9.8%) patients, confirming the importance of making a histological diagnosis prior to initiating treatment. Permanent morbidity was 6.5% and mortality 3.3% and morbidity was balanced by an improvement in 19.6% of the patients following the procedure. For the first 142 patients no peroperative histological diagnosis was available and a diagnostic rate of 86.6% was achieved. For the last 103 patients the availability of peroperative smears improved the diagnostic rate to 94.2% and reduced the number of second biopsies needed for diagnosis from seven to zero. Our series demonstrates the need for peroperative cytology in CT stereotaxic biopsies, and confirms that a complete neuropathology service is a prerequisite for neurosurgical patient care.

An epidemiological survey of primary tumours of the brain and spinal cord in South East Wales.

This survey is founded on 526 patients who presented with a primary tumour of the brain, spinal cord or their coverings over a seven year period. The patients resided in one of the three counties comprising South East Wales, which has a population of about 1.3 million. Each tumour type is classified according to age, sex and area of residence of the patient. Age and sex adjusted annual incidence rates were calculated for each tumour type. All types of glioma have a higher incidence in males, while meningiomas are twice as common in females. Gliomas are the most commonly occurring tumour with an average annual incidence of 3.6 per 100,000 and a peak incidence for malignant astrocytomas of 7.6 in the 55 to 64 year age group. The low grade astrocytoma is the most common tumour of childhood. Oligodendrogliomas occur most commonly in adults between the ages of 35 and 44 years. In this survey there is an unexplained relatively high incidence of oligodendrogliomas. The majority of primary tumours arose in the brain, but there were 24 tumours of the spinal cord, nerve sheath and meninges. Comment is made on the presence and possible aetiological significance of chemical industries within South East Wales.

Intracranial angiolipoma.

Fat containing tumours within the central nervous system are rare. The second reported case of intracranial angiolipoma is described.